Microelectromechanical systems (MEMS) are micromachined devices which include sensors or actuators together with signal processors. These devices are usually fabricated by integrated circuit techniques and have the potential for orders of magnitude decrease in size and cost. An example of MEMS is a micromachined mass spectrometer. A conventional mass spectrometer is large, heavy, and expensive. In addition, a trained technical person is required to operate it.
In order to miniaturize a mass spectrometer, a micromachined device capable of creating a vacuum of about 10 mTorr in a detector chamber of the mass spectrometer is required. This requirement, however, is not fully compatible with integrated circuit applications.
Diaphragms of the art which have been used in MEMS such as miniaturized pumps, when deflected in response to an applied voltage, typically undergo sharp, “witch hat” type deflections. Other diaphragms of the art also utilize high voltages when actuated by electrostatic fields only. These types of deflections are disadvantageous in that they generate high stresses in the diaphragm as well as inefficient pumping action.
A need therefore exists for diaphragms which may be used in, such as, miniature pumps and which address these disadvantages of the prior art.